This invention relates to a method of shaping an object by deforming it with a blast of solid particles.
Among the various known methods of prior art is the ball-shot deformation process, which is described in "Metall" 1977, pages 362-364. According to this process, spherical, or ball-shot blasts which are applied to the surface of the object to be shaped imprint compressive stresses in the superficial layers of the object entailing elongation of the entire surface layer. Furthermore, in the substrate layer tensile stresses are set up resulting in elastic elongation. Since this process can be applied freely, that is to say, without the aid of shaping tools, it has already been widely adopted in the aircraft construction industry for making radiussed wing surfaces and fuselage panels. Any potentially existing differences in respect of section modulus (resistance moments) of the parts is allowed for by an appropriate choice of intensity in the application of the blasting process. Deformations obtained in this fashion are comparable to deformations produced by bending, however, there is a different internal stress distribution in the material. Still more extensive deformations of components can be achieved by increasing blasting pressures and this will result in a reversal of the direction of deformation in the sense that in the area which is subjected to increased blasting pressure the object curves, or arcs towards the opposite side and no longer in the direction towards the blasting source as is normally the case.